A unit of Japanese drugmaker Astellas Pharma will pay the U.S. government $7.3 million to resolve claims it illegally marketed its antifungal drug Mycamine for children before that use was approved.

The investigation began in Philadelphia when lawyer Stephen Sheller filed a whistle-blower lawsuit in federal court here on behalf of a former Astellas sales representative. The U.S. Attorney's Office in Philadelphia was involved in the investigation.

The Justice Department says Astellas' illegal marketing took place between 2005 and 2010. Mycamine was approved for use in adults at the time, but the Food and Drug Administration did not approve its use in children until 2013.

Astellas says it has consistently denied the accusation of illegal marketing and is glad to resolve the dispute. Mycamine is an injection used to prevent and treat fungal infections.

The Justice Department says the federal government will receive $4.2 million from the settlement. Another $3.1 million will go to state Medicaid programs. Medicaid did not cover Mycamine for children because the FDA had not yet approved that use. The whistle-blower will get $709,000. - AP and Inquirer staff